Diphosphines

Abstract

The invention relates to the preparation and use as catalysts of diphosphines of the formula (I) in which R is C 6 -C 14 -aryl or C 4 -C 13 -heteroaryl containing 1 to 3 heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur, wherein the aryl and heteroaryl radicals may optionally be substituted by halogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, and/or trimethylsilyl, and R 1 to R 4 , independently of one another, are each hydrogen, C 1 -C 10 -alkyl, C 1 -C 10 -alkoxy, F, Cl, or Br.

What is claimed is:  
     
       1. A catalyst comprising a metal, metal ion, or metal complex of an element from Group VIII of the Periodic Table of Elements and at least one enantiomerically pure diphosphine of formula (IX)                    
       and enantiomerically pure enantiomers thereof, in which the radicals R″ are in each case identical and are 2-furyl, 2-N-methylpyrrolyl, and 4-fluorophenyl. 
     
     
       2. A catalyst according to  claim 1  wherein the element from Group VIII is ruthenium, iridium, or rhodium.